It eats up ­motorway miles with effortless disdain. Photographs: Simon Stuart-Miller

This would be the poshest car I've ever driven – ever been in probably – if it weren't for that Bentley I had the other day. But because of that it feels I'm on a downward trajectory, socioeconomically speaking. What, no walnut picnic tables? It costs less than £100,000? Pah!

Still, I'll have to make do, I suppose. And its arrival is timely; I'm off to a stud farm in Newmarket and this feels like the right car to be going in. The stud belongs to a sheikh, and there's something of Arab wealth about the Mercedes CL coupe. Expensive but not super-ostentatious, luxurious, fast. It's more elegant than its four-door S-Class sister.

The Mercedes CL eats up motorway miles with effortless disdain. There's little for the driver to do – the car monitors the traffic around, keeps a safe distance from the car in front. It can even steer me back into my lane if I wander into the neighbouring one, though to be honest I didn't figure out how to implement that particular safety feature, Active Lane-Keeping Assist, it's called. Anyway, I'm still pretty much redundant, I'll watch a movie… Oh, they've made it so only the person in the front passenger seat can watch films when the car is going along. Well, I'm not doing anything here, I may as well go and sit over there.

Off the motorway, and this car is more fun. There's more to do, and it feels remarkably agile for such a big beast. A big powerful beast – 435 horsepower, but refined horsepower; thoroughbred horsepower.

At the imposing gates of the sheikh's stud, the security guard raises the barrier and waves me straight through, mistaking me for the right kind of person from my car, I imagine. That wouldn't have happened if I'd come in our old Polo, with the moss growing on the roof. Driving slowly along the drive, through immaculate paddocks where shiny mares graze and their new foals skip, it all feels, well, right really.

Later, in the "covering shed", I witness horse sex. This is for work (kinda), not just for kicks, promise. The fella horse is pretty impressive, with his shuddering flanks and all the rest of it. It's nice to know that on the way home I'll have 435 of him available to me, under my right foot. Brrrmmmprrr (that's like a cross between the rumble of a 4.6-litre V8 engine and a horse snort).

One go with this particular stallion, Dubawi, costs a little over half the price of the car. Two equestrian shags, or a Mercedes CL500 coupe. It's a close one: Dubawi is magnificent, but I think I'll take the car.